CN111051689A

CN111051689A - Wave receiving mechanism

Info

Publication number: CN111051689A
Application number: CN201980004353.XA
Authority: CN
Inventors: 丸山康树; 林昌奎; 小林豪毅; 栗林直树
Original assignee: University of Tokyo NUC; Kawasaki Jukogyo KK
Current assignee: University of Tokyo NUC; Kawasaki Motors Ltd
Priority date: 2018-02-07
Filing date: 2019-02-06
Publication date: 2020-04-21
Anticipated expiration: 2039-02-06
Also published as: JP2019138173A; US11739728B2; EP3751130A4; WO2019156109A1; JP6967223B2; US20200400115A1; KR102191824B1; CN111051689B; EP3751130B1; KR20200003172A; EP3751130A1

Abstract

The wave receiving mechanism includes: a shaft connected to the hydraulic pump and driving the hydraulic pump by rotating to one side and the other side in a circumferential direction; and a wave receiving member having an arm that is attached to the shaft so as to be relatively non-rotatable, and a wave receiving plate that is provided on the arm so as to receive a force of waves, the wave receiving member being adapted to rock about the shaft and to swing the shaft by the rock when receiving the force of the waves; the arm has a first arm part which is mounted on the shaft in a manner of being incapable of rotating relatively, a second arm part provided with a wave receiving plate, and a foldable part for connecting the first arm part and the second arm part; the foldable portion is configured to rock the first arm and the second arm integrally when the swing angle of the first arm is smaller than a first predetermined angle, and to allow the second arm to be folded with respect to the first arm when the swing angle of the first arm is the predetermined angle.

Description

Wave receiving mechanism

Technical Field

The present invention relates to a wave receiving mechanism that receives a wave force to swing and thereby drive a hydraulic pump.

Background

A natural energy power generation system using various natural energies such as wind energy and solar energy is put to practical use, and a wave power generation system is known as one of the natural energy power generation systems. The wave power generation system converts the force of waves, i.e., the energy of the waves, into mechanical energy at a time, and further converts the mechanical energy into electric energy. As a wave power generation system having such a function, for example, there is a wave power generation system described in patent document 1.

In the wave power generation system of patent document 1, a shaft is rotatably supported by a pair of bearing members, and a wave receiving member is relatively non-rotatably attached to the shaft. Therefore, when the wave receiving member rocks, the shaft rotates in one and the other directions in the circumferential direction. The shaft is connected to a pump device. The pump device is a plunger cylinder (ram cylinder) type pump. That is, the rod reciprocates as one and the other of the axial directions and the circumferential directions rotate, and the working fluid is discharged from the pump device. The discharged hydraulic fluid is supplied to the hydraulic motor, and the hydraulic motor rotates its output shaft by the supplied hydraulic fluid. A generator is attached to an output shaft of the hydraulic motor, and the generator generates electric power by rotation of the output shaft.

Prior art documents:

patent documents:

patent document 1: japanese patent laid-open publication No. 2015-108344.

Disclosure of Invention

The problems to be solved by the invention are as follows:

in the wave power generation system of patent document 1, when the wave receiving member receives the force of a wave, the rod travels a stroke corresponding to the force of the wave, and the working fluid is discharged from the pump device at a flow rate corresponding to the stroke amount. The flow rate of the working fluid discharged from the pump device is determined according to the discharge capacity thereof, and the discharge capacity of the pump device used is determined as follows.

That is, since the waves received by the wave receiving member are natural energy, the height thereof is not constant but changes from moment to moment. Therefore, the wave power generation system needs to cope with waves of all heights, and the capacity of the pump device is determined so that the operation rate of the wave power generation system is maximized with respect to the waves of all heights in order to cope with the waves. On the other hand, it is difficult to cope with waves of all heights in reality, and the capacity of the pump device is actually determined according to the height of the waves having a relatively high frequency among the generated waves. However, the wave receiving member may receive waves larger than the assumed waves, and in such a case, the wave receiving member is greatly swung, and thus various structures of the wave power generation system such as the pump apparatus may be damaged.

To cope with such a situation, the wave power generation system includes a stopper so as not to rock the wave receiving member more largely than an assumed angle when the wave receiving member receives a large wave. The stopper contacts the wave receiving member when the wave receiving member swings to a predetermined angle, and regulates swing of the wave receiving member by the contact. This prevents the pump device from being damaged by the rod stroke beyond the expected stroke. However, since the swing of the wave receiving member is restricted by the stopper, the wave receiving member must receive the force of the waves all over the pan. In order to allow the wave receiving member to receive such a wave force, the wave receiving mechanism is increased in size and manufacturing cost is increased. Therefore, in order to prevent the wave receiving member from being damaged, it is preferable that a large wave force be able to be avoided when acting on the wave receiving member.

It is therefore an object of the present invention to provide a wave receiving mechanism capable of avoiding a large wave force when the wave force acts on a wave receiving member.

Means for solving the problems:

the wave receiving mechanism of the present invention includes: a shaft which is rotatably supported while being connected to a hydraulic pump and which drives the hydraulic pump by rotating in one circumferential direction and in the other circumferential direction; and a wave receiving member having an arm that is attached to the shaft so as to be relatively non-rotatable, and a wave receiving plate that is provided to the arm so as to receive a force of a wave, the wave receiving member being configured to rock about the shaft and swing the shaft by rocking when receiving the force of the wave; the arm has a first arm portion attached to the shaft so as not to be relatively rotatable, a second arm portion provided with the wave receiving plate, and a foldable portion connecting the first arm portion and the second arm portion; the foldable portion is configured to rock the first arm integrally with the second arm when the swing angle of the first arm is smaller than a first predetermined angle, and to allow the second arm to be folded with respect to the first arm when the swing angle of the first arm is the predetermined angle.

According to the present invention, since the first arm and the second arm are integrally rock when the angle is smaller than the predetermined angle, the hydraulic pump can be driven by the force of the waves transmitted to the shaft. On the other hand, when the wave force is large and the swing angle of the first arm reaches the predetermined angle, the second arm is bent with respect to the first arm. Thus, the wave receiving plate can avoid the force of the waves, and thus, the excessive force can be prevented from acting on the wave receiving plate. That is, damage to the wave receiving member can be suppressed. Thus, a wave receiving mechanism capable of receiving large waves without increasing the size can be manufactured.

Further, in the present invention, since the force of the wave can be avoided by bending the second arm portion, it is possible to suppress transmission of a large wave force from the wave receiving plate to the shaft via the second arm portion and the first arm portion, and it is possible to suppress damage of the shaft and the hydraulic pump due to such a large wave force.

In the above invention, the foldable portion may include an engaging portion provided on one of the first arm and the second arm and an engaged portion provided on the other of the first arm and the second arm and engaged with the engaging portion, and the first arm and the second arm may be integrally swung by engaging the engaging portion and the engaged portion, and the second arm may be allowed to be folded with respect to the first arm by releasing the engagement of the engaging portion and the engaged portion.

According to the above configuration, since the second arm portion can be bent with respect to the first arm portion by a simple operation of releasing only the engagement, it is possible to suppress an increase in the number of components of the wave receiving mechanism and the manufacturing cost.

In the above-described invention, the swing arm may further include an engagement releasing member that is brought into contact with the foldable portion of the swing wave-receiving member, and that releases the engagement between the engaging portion and the engaged portion by swinging the first arm portion in the contact state.

According to the above configuration, when the first arm is swung to reach the predetermined angle in a state where the engagement releasing member is in contact with the foldable portion, the engagement is automatically released. Therefore, the engagement releasing member can be simply configured without having a complicated function for releasing the engagement.

In the above invention, either one of the engaging portion and the engaged portion may have a roller rotatably supported by a portion engaged with the other member; the roller rolls on the other member when the engagement between the engaging portion and the engaged portion is released.

According to the above configuration, the roller can be rolled on the other portion. This can prevent the engagement from being in a state where the bending is impossible.

In the above invention, the swing mechanism may further include a stopper member that is brought into contact with the first arm when the first arm is swung to a second predetermined angle equal to or greater than the first predetermined angle, and limits the swing of the first arm.

According to the above configuration, it is possible to suppress further pivoting of the shaft by continuing to rock the first arm even after the second arm is bent.

In the above invention, the wave receiving shaft as the shaft and the pump shaft of the hydraulic pump may be connected to each other by a flexible joint having respective axes parallel to each other; the flexible joint allows relative displacement of the wave receiving axis with respect to the pump shaft in a direction orthogonal to the axis.

According to the above configuration, even when the wave receiving shaft is deflected or twisted by the wave force received by the wave receiving member, the flexible joint can absorb the deflection and the torsion. Thus, even if the wave receiving shaft is bent or twisted, the wave receiving shaft and the pump shaft can be prevented from being damaged.

The invention has the following effects:

according to the present invention, a large wave force can be avoided when the wave receiving member is acted on by the wave.

Drawings

Fig. 1 is a perspective view showing a wave power generation system of a first embodiment;

fig. 2 is a front view showing an outline of the wave power generation system of fig. 1;

fig. 3 is a side view of the wave power generation system of fig. 2 as viewed from the side;

fig. 4 is a side view showing an enlargement of a wave receiving mechanism of the wave power generation system of fig. 3;

fig. 5 is an enlarged side view showing an area X of the wave receiving mechanism of fig. 4 in an enlarged manner;

fig. 6 is an enlarged perspective view of the wave receiving mechanism of fig. 4 as viewed obliquely from above;

fig. 7 is an enlarged side view showing a state in which the wave receiving mechanism of fig. 4 is located at a neutral position;

fig. 8 is an enlarged side view showing a state in which the wave receiving mechanism is rocked in a predetermined direction from the neutral position;

fig. 9 is an enlarged side view illustrating a state in which a locking pin of the swing wave receiving mechanism is in contact with the release lock;

fig. 10 is an enlarged side view showing a state where the hook of the wave receiving mechanism is pushed open by the engagement releasing lever;

fig. 11 is an enlarged side view showing a state in which the lower arm portion is bent with respect to the upper arm portion;

FIG. 12 is a perspective view taken from and showing a flexible joint and its vicinity in the wave power generation system of FIG. 2;

FIG. 13 is a cross-sectional view taken along section line XIII-XIII and showing the flexible joint shown in FIG. 12.

Detailed Description

Hereinafter, a wave power generation system 1 according to an embodiment of the present invention will be described with reference to the drawings. Note that the concept of direction used in the following description is used for convenience of description, and the direction of the structure of the invention and the like are not limited to this direction. The wave power generation system 1 described below is only one embodiment of the present invention. Therefore, the present invention is not limited to the embodiments, and additions, deletions, and modifications may be made without departing from the scope of the invention.

< wave power generation system >

The wave power generation system 1 shown in fig. 1 is a power generation system that converts wave force, i.e., wave energy, which is the force of waves that have flown into the coast into electric energy to generate electric power, and is provided in front of (i.e., on the sea side of) a breakwater 2 provided on the coast. Specifically, a concrete sinker (e.g., six support piles 3) is provided on the seabed near the breakwater 2, and a plurality of (e.g., six) support piles are erected on the concrete sinker. A floor 4 having a substantially rectangular shape in plan view is mounted and fixed on the plurality of column piles 3, and a waterproof compartment 5 is provided on the floor 4. The waterproof cabin 5 accommodates a part of the structure of the wave power generation system 1 (for example, a pump device 20 described later). The wave power generation system 1 thus configured is configured as a steel marine jacket structure, and includes a pair of pendulum-type

wave receiving mechanisms

10L and 10R as shown in fig. 2 and 3 in order to convert wave energy into electric energy.

< wave receiving mechanism >

The pair of

wave receiving mechanisms

10L and 10R are provided on the floor 4 so as to be separated in a direction (left-right direction on the paper surface) substantially perpendicular to the waves coming to the coast, for example. The pair of

wave receiving mechanisms

10L and 10R thus arranged have the same configuration, and the configuration of one wave receiving mechanism 10R will be described below, while the configuration of the other wave receiving mechanism 10L will be denoted by the same reference numeral and the description thereof will be omitted. The one wave receiving mechanism 10R includes a pair of

support bases

11 and 11, a steering shaft 12, and a wave receiving member 13 so as to rock by the force of waves coming to the coast. The pair of support stands 11, 11 are provided on the floor 4 so as to be separated in the left-right direction, and are inserted by the rudder shaft 12. The rudder shaft 12 is a long, substantially cylindrical member extending in the left-right direction. One end portion and the other end portion of the rudder shaft 12 are rotatably supported by a pair of

support bases

11 and 11, respectively, and a wave receiving member 13 is attached to an intermediate portion thereof.

The wave receiving member 13 receives waves surging to the coast and rocks, thereby rotating the control shaft 12. The wave receiving member 13 having such a function has a pair of

arms

14, 14 and a wave receiving plate 15. The pair of

arms

14, 14 are long members extending in the vertical direction, and their upper end portions are attached to the rudder shaft 12 so as not to be relatively rotatable. The pair of

arms

14, 14 are attached to the steering shaft 12 so as to be separated from each other in the left-right direction. An opening 4a is formed in the floor 4 below the steering shaft 12 and between the pair of support bases 11, and the pair of

arms

14, 14 hang downward from the steering shaft 12 toward the sea surface 6 through the opening 4 a. The lower end portions of the pair of

arms

14, 14 thus configured reach near the sea surface 6, where the wave-receiving plate 15 is arranged.

The wave receiving plate 15 is a plate having a substantially rectangular shape when viewed from the rear (i.e., the breakwater 2 side), and most of the plate except for the upper side thereof is positioned below the sea surface 6, i.e., submerged in the sea. The wave receiving plate 15 is disposed such that the front surface and the rear surface thereof are substantially parallel to the breakwater 2, and receives a wave (incident wave) coming from the sea side at the front surface and receives a force of a wave (reflected wave) reflected by the breakwater 2 and its vicinity at the rear surface. In this way, the wave receiving member 13 receives a wave force on the wave receiving plate 15, thereby swinging about the control shaft 12. The wave receiving member 13 swings the control shaft 12 about its axis.

The pair of

wave receiving mechanisms

10L and 10R can rotate the steering shaft 12 by receiving the wave force on the wave receiving member 13. In addition, as will be described in detail later, the pair of

wave receiving mechanisms

10L and 10R are configured such that the longitudinal intermediate portions of the pair of

arms

14 and 14 can be bent, and when a large wave is incident on the

wave receiving mechanisms

10L and 10R, the longitudinal intermediate portions are bent to avoid the force of the wave. The pair of

wave receiving mechanisms

10L and 10R configured as described above are disposed on the floor 4 so that the axes of the steering shafts 12 are substantially on the same line and are separated in the left-right direction. A fixed base 7 provided on the floor 4 is disposed between the pair of

wave receiving mechanisms

10L, 10R disposed so as to be separated from each other, and a pump device 20 is provided on the fixed base 7.

The pump device 20 is a plunger cylinder type pump, and is connected to each of the pair of steering shafts 12. When the pair of steering shafts 12 rotate, the pump device 20 sucks and discharges the hydraulic fluid (oil, water, or the like) in accordance with the rotation. The pump device 20 having such a function has a pump shaft 21, a pair of

cylinder mechanisms

22U, 22D, and a tiller (tiller) 23. The pump shaft 21 is a substantially cylindrical member and extends in the left-right direction. The pump shaft 21 is disposed so that its axis is coaxial with the axes of the pair of rudder shafts 12. The steering shafts 12 of the pair of

wave receiving mechanisms

10L and 10R are connected to both ends of the pump shaft 21 disposed in this manner via flexible joints 16. The flexible joint 16 is configured to transmit the rotation force of the rudder shaft 12 to the pump shaft 21 while absorbing the deflection, torsion, and the like of the rudder shaft 12, as will be described later. This enables the rotational force of the steering shaft 12 to be reliably transmitted to the pump shaft 21. The pump shaft 21 thus configured penetrates the fixed base 7, and both end side portions thereof are rotatably supported by the fixed base 7.

The fixed base 7 is provided with a pair of

cylinder mechanisms

22U, 22D. The pair of

cylinder mechanisms

22U and 22D are disposed above and below the pump shaft 21, respectively. The pair of

cylinder mechanisms

22U and 22D arranged in this manner are so-called plunger cylinder mechanisms, and have the same configuration. That is, each of the pair of

cylinder mechanisms

22U and 22D has a rod 25 and a pair of

cylinders

26a and 26b, and the working fluid can be discharged from each of the pair of

cylinders

26a and 26b by reciprocating the rod 25.

The pair of

cylinder mechanisms

22U and 22D configured as described above are disposed such that the respective rods 25 are orthogonal to the pump shaft 21 in plan view and overlap each other. The levers 25 and the pump shaft 21 are coupled by the tiller 23, and the tiller 23 converts the rotational motion of the pump shaft 21 into the linear reciprocating motion of the lever 25. Therefore, the working fluid can be discharged from the pair of

cylinder mechanisms

22U and 22D by rotating the pump shaft 21.

The pump device 20 is connected to the hydraulic motor via a hydraulic drive circuit, not shown, and the discharged hydraulic fluid is supplied to the hydraulic motor via the hydraulic drive circuit. However, the working fluid discharged from the pump device 20 pulsates, and if the working fluid is supplied to the hydraulic motor in this manner, the hydraulic motor cannot be operated smoothly. Therefore, in the hydraulic drive circuit, the pulsating working fluid is averaged by an accumulator not shown, and then supplied to the hydraulic motor to drive the hydraulic motor. In the hydraulic drive circuit, the flow rate and pressure of the hydraulic fluid, which are averaged, are adjusted, and the output of the hydraulic motor is adjusted. An electric generator, not shown, is connected to the output shaft of the hydraulic motor whose output is adjusted in this manner. Thus, electric power can be generated in the generator by driving the hydraulic motor. The electric power thus generated is adjusted in voltage, frequency, and phase by a power conditioner, not shown, and then transmitted to the electric power system. In this way, in the wave power generation system 1, electric power can be generated by the energy of the waves.

[ wave receiving mechanism ]

In the wave power generation system 1 configured as described above, when a large wave is generated toward the wave receiving plate 15, the longitudinal intermediate portions of the pair of

arms

14 and 14 can be bent to avoid the force of the wave. That is, the

wave receiving mechanisms

10L and 10R are foldable wave receiving mechanisms. The configuration of the pair of

arms

14, 14 of the

wave receiving mechanisms

10L, 10R having such a function will be described in detail below. Since the pair of

arms

14 and 14 have the same configuration, only the configuration of one arm 14 will be described, and the configuration of the other arm 14 will not be described.

The arm 14 has an upper arm portion 31, a lower arm portion 32, and a ratchet 33, as shown in fig. 4. The upper arm 31 is a vertically long member, and an upper end portion as one end portion in the longitudinal direction thereof cannot be attached to the rudder shaft 12. A lower arm portion 32 is provided at the lower end of the upper arm portion 31 via a ratchet 33. The lower arm portion 32 is also a vertically elongated member, and the wave receiving plate 15 is integrally formed at the lower end portion thereof. The wave receiving plate 15 is provided so as to be bridged over the lower end portions of the lower arm portions 32 of the pair of arms 14, and receives the force of the incident wave and the reflected wave as described above. As described above, the ratchet 33 is interposed between the two

arm portions

31 and 32 configured as described above, and the two

arm portions

31 and 32 are coupled to each other by the ratchet 33.

The ratchet 33 as a foldable portion is configured as follows in order to rock the upper arm 31 and the lower arm 32 integrally and allow the lower arm 32 to be folded with respect to the upper arm 31 when the wave receiving member 13 reaches a predetermined rocking angle. That is, the ratchet 33 further has a hinge 34 as shown in fig. 5 and 6. The hinge 34 is a portion for enabling the lower arm 32 to be bent with respect to the upper arm 31, and includes an upper connecting body 34a, a lower connecting body 34b, and a hinge pin 34 c.

As is apparent from fig. 6, the upper connecting body 34a is formed in a substantially inverted U shape when viewed from the rear, and has a pair of side walls 34d arranged at a left-right interval. The upper connecting body 34a has the lower connecting body 34b inserted between the pair of side walls 34 d. The lower connecting body 34b is a long plate member extending in the vertical direction and having a width in the front-rear direction, and its upper end portion is inserted between the pair of side walls 34 d. A hinge pin 34c is inserted into the pair of side walls 34d to collectively penetrate the upper end side portion of the lower link body 34b, and the lower link body 34b is rockably moved in the front-rear direction about the hinge pin 34 c. A lower portion of the lower connecting body 34b projects downward from the pair of side walls 34d, and a lower arm 32 is fixed to a lower end side portion of the lower connecting body 34 b. Thereby, the lower arm 32 and the lower connecting body 34b operate integrally.

The hinge 34 configured as described above can rock the lower connecting body 34b with respect to the upper connecting body 34a, thereby folding the lower arm 32 with respect to the upper arm 31. On the other hand, the ratchet wheel 33 is configured as follows so as not to bend when the wave is small. That is, the ratchet 33 has a pair of hooks 35, and the upper arm 31 and the lower arm 32 can be integrally operated by the pair of

hooks

35, 35.

That is, the pair of

hooks

35, 35 are formed in a substantially J-shape in side view, and are bent so that tip end side portions thereof are bent. The pair of

hooks

35, 35 having such a shape are inserted with their base end side portions between the pair of side walls 34d of the upper connecting body 34 a. That is, the lower connecting body 34b is disposed between the pair of side walls 34d and the top surface of the upper connecting body 34a with a space therebetween, and the proximal end side portions of the pair of

hooks

35, 35 are inserted into the space from both the left and right sides. A pivot pin 36 is inserted into the base end side portions of the pair of

hooks

35, 35 so as not to be rotatable relative to each other. The pivot pin 36 extends in the left-right direction, and both ends thereof are rotatably supported by the pair of side walls 34 d. The pair of

hooks

35, 35 are provided on the upper link body 34a so as to be rotatable about the rotation pin 36. The pair of

hooks

35, 35 thus configured have a substantially inverted V-shape in side view, and are arranged such that their respective curved tip end portions face in the direction of the opposite hook 35, i.e., face each other.

An arc-shaped space is formed between the pair of

hooks

35, 35 thus arranged. The arc-shaped space is formed along the inner surfaces thereof, and the tip end side portions of the pair of

hooks

35, 35 are located on one side and the other side in the circumferential direction. An upper end portion of the lower connecting body 34b is disposed between tip end portions of the pair of hooks 35, and an engaged portion 34e located at the upper end portion of the lower connecting body 34b protrudes into the arc-shaped space. The engaged portion 34e is formed in an arc shape in accordance with the shape of the arc-shaped space, and is accommodated in the circular space. The distal end portions of the pair of

hooks

35, 35 abut against and engage with circumferential end portions of the engaged portion 34e of the lower connecting body 34 b. As described above, the distal end portions of the pair of

hooks

35 and 35 are engaged with the engaged portion 34e, whereby the swing of the lower connecting body 34b is prevented. In order to maintain the engagement between the distal end side portions of the pair of

hooks

35, 35 and the engaged portion 34e, biasing members 37 are provided on the pair of hooks 35, respectively, in correspondence with each other.

The urging member 37 is a so-called torsion spring whose coil portion is externally fitted on the rotating pin 36 inserted into the corresponding hook 35. The biasing member 37 externally fitted in this manner is disposed between the corresponding hook 35 and the side wall 34 d. Further, the pair of

hooks

35, 35 are each formed with a locking pin 35a on one side surface thereof, and the locking pin 35a is formed to protrude from the side surface. The pair of

hooks

35, 35 having the locking pin 35a formed as described above are arranged such that the one side surfaces face in opposite directions to each other, and thereby the locking pin 35a protrudes in mutually different directions in the left-right direction. The two biasing

members

37, 37 are externally attached to the pivot pin 36 so as to be positioned on one side surface side of the pair of

hooks

35, 35 with respect to the pair of

hooks

35, 35 configured as described above. The biasing member 37 externally fitted in this manner has one end portion thereof locked to the locking pin 35a of the corresponding hook 35 and the other end portion thereof locked to the top surface of the upper connecting body 34 a. The biasing member 37 thus arranged biases the corresponding hook 35 about the pivot pin 36 in a direction in which the tip end side portion of the hook 35 is pressed against the engaged portion 34e, that is, in a direction in which the locking pin 35a is pushed downward. This maintains the engagement between the pair of

hooks

35, 35 and the lower connecting body 34b, and prevents the lower connecting body 34b from being bent with respect to the upper connecting body 43a, that is, the lower arm portion 32 from being bent with respect to the upper arm portion 31.

The pair of

hooks

35, 35 can be rotated in a direction opposing the biasing force of the biasing member 37 to disengage the distal end portions thereof from the engaged portions 34e, and the engagement between the hooks 35 and the engaged portions 34e can be released. The pair of

hooks

35, 35 each prevent the lower connecting body 34b from swinging in one circumferential direction by engaging one of the hooks 35 with the lower connecting body 34b, and prevent the lower connecting body 34b from swinging in the other circumferential direction by engaging the other hook 35 with the lower connecting body 34 b. Therefore, when the engagement between one of the hooks 35 and the engaged portion 34e is released, the lower connecting body 34b is allowed to rock in the circumferential direction, and when the engagement between the other hook 35 and the engaged portion 34e is released, the lower connecting body 34b is allowed to rock in the circumferential direction.

In this way, the ratchet 33 can cause the lower connecting body 34b and the upper connecting body 34a to integrally operate by engaging the pair of

hooks

35, 35 with the engaged portion 34 e. The ratchet 33 allows the lower connecting body 34b to be bent with respect to the upper connecting body 34a by rotating the hook 35 and releasing the engagement with the engaged portion 34 e. In the pair of

hooks

35 and 35, rollers 38 are provided on the portions where the hooks 35 engage with the engaged portions 34e, that is, on the tip end side portions of the hooks 35, in order to smoothly release the engagement between the hooks 35 and the engaged portions 34 e.

The roller 38 is supported rotatably about an axis extending in the left-right direction, and is arranged to contact the engaged portion 34e during engagement. Therefore, when the

hooks

35 and 35 are rotated to release the engagement, the roller 38 rolls (i.e., rolls) on the surface of the engaged portion 34 e. That is, the surface shape of the engaged portion 34e is formed in a substantially circular arc shape having the rotation pin 36 as a rotation center and a radius of a distance to the contact surface of the roller 38. This enables the roller 38 to roll smoothly on the surface of the engaged portion 34 e. The surface shape of the engaged portion 34e is formed so that the radius thereof gradually increases from the tip end to the base end side in order to absorb the gap caused by the radius error.

By providing the rollers 38 at the distal end side portions of the hooks 35 in this manner, the rollers 38 can be rolled on the surfaces of the engaged portions 34e when the engagement is released, and the engagement can be smoothly released (that is, the engagement cannot be released all the time) by suppressing the engagement of the engaged portions 34e at the distal end side portions of the hooks 35. Further, the roller 38 can be rolled on the surface of the engaged portion 34e even at the time of engagement, and therefore, smooth engagement can be achieved. The wave receiving mechanism 10R capable of smoothly performing engagement and disengagement in this manner includes a pair of

disengagement levers

39F and 39R for disengaging the engagement.

The pair of

release levers

39F and 39R are formed in a substantially L shape and are provided vertically on the floor panel 4 so as to be positioned in front of and behind the opening 4a of the floor panel 4. That is, the pair of

release levers

39F and 39R extend downward from the floor panel 4, and are bent in a direction to approach each other at intermediate portions thereof. The bent portion extends so as to be inclined downward in a direction approaching each other, closer to the tip end side of the tip. The pair of

release levers

39F and 39R having such a shape are disposed so as to correspond to the locking pins 35a of the pair of

hooks

35 and 35, respectively. That is, the release levers 39F and 39R are arranged to be shifted in the left-right direction in accordance with the corresponding locking pins 35 a. The release levers 39F and 39R thus arranged come into contact with the locking pins 35a of the corresponding hooks 35 when the wave receiving member 13 is greatly swung toward the sea side and the breakwater 2 side, respectively.

For example, when the wave receiving member 13 is rocked largely toward the breakwater 2, the locking pin 35a of one of the hooks 35 contacts the rear-side release lever 39R (see fig. 5) located on the breakwater 2 side, and when the wave receiving member 13 is rocked largely toward the sea side, the locking pin 35a of the other hook 35 contacts the front-side release lever 39F located on the sea side. When the wave receiving member 13 is further rocked toward the breakwater 2 side or the sea side by bringing the release levers 39F and 39R into contact with the locking pins 35a of the corresponding hooks 35 in this manner, the hooks 35 are pushed in the direction opposite to the direction of rocking. Thereby, the corresponding hook 35 is rotated in a direction away from the engaged portion 34e, and the engagement between the hook 35 and the engaged portion 34e is released. As described above, the release levers 39F and 39R are brought into contact with the locking pin 35a to swing the wave receiving member 13, so that the hook 35 can be pivoted in a direction against the biasing force to release the engagement between the hook 35 and the engaged portion 34 e.

More specifically, when the wave receiving member 13 is swung to a first predetermined angle (for example, in a range of 30 degrees to 34 degrees, in the present embodiment, 30 degrees) toward the breakwater 2 and the sea, the pair of

release levers

39F and 39R release the engagement between the hook 35 and the engaged portion 34 e. That is, each of the pair of

release levers

39F and 39R is brought into contact with the corresponding locking pin 35a when the wave receiving member 13 is rocked toward the breakwater 2 and the sea side, and releases the engagement between the hook 35 and the engaged portion 34e when the hook 35 is rotated with respect to the further wavereceiving member 13 and reaches the first predetermined angle. In the present embodiment, the first predetermined angle is set to be the same angle on the breakwater 2 side and the sea side, but it is not necessarily the same, and may be different. The wave receiving mechanism 10R configured as described above includes a pair of

stoppers

41F and 41R for restricting the swinging of the wave receiving member 13, more specifically, the upper arm 31 beyond a second predetermined angle.

The pair of

stoppers

41F and 41R are formed in a substantially L shape, similarly to the pair of

release levers

39F and 39R, and are provided vertically on the floor 4 so as to be positioned in front of and behind the opening 4 a. That is, the pair of

stoppers

41F and 41R extend downward from the floor 4, and are bent at intermediate portions thereof in a direction to approach each other. The tip end side portions closer to the tip end than the bent portions extend so as to be inclined downward in a direction of approaching each other. The pair of

stoppers

41F and 41R having such a shape are disposed corresponding to the upper connecting body 34a, respectively, and the release levers 39F and 39R are brought into contact with the upper connecting body 34a when the wave receiving member 13 is greatly swung toward the sea side and the breakwater 2 side, respectively.

For example, when the wave receiving member 13 is greatly rocked toward the breakwater 2, the rear stopper 41R positioned on the breakwater 2 side is in contact with the upper connecting body 34a (see fig. 5), and when the wave receiving member 13 is greatly rocked toward the sea side, the front stopper 41F positioned on the sea side is in contact with the upper connecting body 34 a. By the contact, the operation of the upper link 34a is stopped, and the swing of the upper arm 31 is restricted. The pair of stoppers 41L and 41R having such a function come into contact with the upper connecting body 34a when the wave receiving member 13 swings toward the breakwater 2 and the sea side by a second predetermined angle (for example, 30 degrees or more and 34 degrees or less and 30 degrees or more in the present embodiment), respectively, to regulate swing of the upper arm 31.

The operation of the wave receiving mechanism 10R configured as described above will be described with reference to fig. 7 to 11. In the wave receiving mechanism 10R, the wave receiving plate 15 receives a force of waves mainly, and the receiving plate rocks toward the breakwater 2 and toward the sea by the waves receiving the force. That is, the wave receiving member 13 rocks to the sea side by the force of the input waves that have flown from the sea side, and rocks to the sea side by the force of the reflected waves that have been reflected by the breakwater 2. The wave receiving member 13 (i.e., the upper arm 31) thus rocked basically within an angular range equal to or smaller than the first predetermined angle toward the breakwater 2 and the sea side, except when receiving a large wave force generated during a typhoon or the like (see, for example, fig. 7 and 8). In this case, since the release levers 39F and 39R do not contact the locking pins 35a and 35a of the pair of

hooks

35 and 35, the pair of

hooks

35 and 35 are pressed and engaged with the engaged portion 34e by the biasing

members

37 and 37, and the upper arm portion 31 and the lower arm portion 32 are integrally operated by the ratchet 33. Accordingly, the wave receiving member 13 can supply the torque corresponding to the force of the input waves and the force of the reflected waves to the pump device 20 via the control shaft 12, and thus can generate the electric power corresponding to the torque in the generator.

On the other hand, when a large wave is generated as in a typhoon, the upper arm 31 of the wave receiving member 13 may rock by the wave toward the breakwater 2 and toward the sea beyond a first predetermined angle (see, for example, fig. 9 to 11). In this case, the wave receiving member 13 operates as follows. That is, when the upper arm 31 of the wave receiving member 13 is swung, the locking pin 35a is brought into contact with the release levers 39F and 39R. For example, as shown in fig. 9, when the upper arm 31 is rocked toward the breakwater 2, the locking pin 35a of the one hook 35 contacts the release lever 39R. When the upper arm 31 is further swung toward the breakwater 2 in this state, the one hook 35 is pushed toward the sea side. Thereby, the roller 38 rolls on the surface of the engaged portion 34 e. Thereafter, when the swing angle of the upper arm 31 toward the breakwater 2 is a first predetermined angle, the distal end portion of the hook 35 is disengaged from the engaged portion 34e, and the engagement between the hook 35 and the engaged portion 34e is released (see fig. 10).

In the state where the engagement is released in this manner, the lower connecting body 34b is allowed to swing in one circumferential direction. Therefore, when the wave receiving plate 15 receives a force of further incident waves, the lower connecting body 34b pivots about the hinge pin 34c, and the lower arm 32 rocks so as to be bent toward the breakwater 2 with respect to the upper arm 31 (see fig. 11). When the upper arm 31 is swung to the first predetermined angle in this manner, the lower arm 32 is bent with respect to the upper arm 31. This allows the wave receiving member 13 to be pushed by a large wave to avoid the force. Therefore, it is possible to suppress breakage of the wave receiving member 13 when a large wave occurs, and it is possible to manufacture the

wave receiving mechanisms

10L and 10R that can receive such a large wave without increasing the size. Further, by avoiding the force of large waves by the wave receiving member 13, it is possible to suppress excessive torque from being transmitted to the pump device 20 via the upper arm 31 and the steering shaft 12. This can suppress damage to the pump device 20 when a large wave occurs as in a typhoon.

The wave receiving member 13 receives a part of the force of the incident waves while avoiding the force by bending the lower arm 32, and the force is transmitted to the upper arm 31 via the ratchet 33. Thus, the upper arm portion 31 continues to rock to the second predetermined angle beyond the first predetermined angle even after the release although the swing is slower than before the release. When the upper link 34a is then pivoted to the second predetermined angle, the swing of the upper arm 31 is restricted by the upper link contacting the stopper 41R. By restricting the swing of the upper arm 31 in this manner, the rotation of the steering shaft 12 is also restricted. This prevents the rod 25 connected to the rudder shaft 12 via the pump shaft 21 and the rudder stock 23 from being stroked by a predetermined amount or more, and prevents the pump device 20 from being damaged by the stroke of the predetermined amount or more.

In this way, the wave receiving member 13 can bend the lower arm portion 32 when a large input wave comes in, and can avoid the force of the input wave. After the engagement is released, when the wave receiving member 13 swung to the breakwater 2 side is rocked to the sea side, the engagement is again performed in a procedure reverse to the above procedure. That is, when the upper arm 31 is returned, the hook 35 is engaged with the engaged portion 34e again up to the first predetermined angle, and thus the swing is performed toward the sea side. In addition, when the reflected wave is also large, the lower arm portion 32 can be bent toward the sea side to avoid the force of the reflected wave, as in the case where the incident wave is large.

That is, when the upper arm 31 is greatly rocked by the reflected waves, the locking pin 35a of the other hook 35 eventually comes into contact with the release lever 39F. By further movement, the other hook 35 is pushed toward the breakwater 2 side relative to the lower connecting body 34 b. When the upper arm 31 is then swung to the sea side by the first predetermined angle or more, the tip end portion of the other hook 35 comes off from the engaged portion 34e, and the engagement between the hook 35 and the engaged portion 34e is released. Thereafter, when the wave receiving plate 15 continues to receive the force reflecting the waves, the lower arm 32 is rocked to the sea side with respect to the upper arm 31 in order to avoid the force. The upper arm 31 continues to rock beyond the first predetermined angle to the second predetermined angle even after the swing. When the swing is performed to the second predetermined angle, the upper link 34a contacts the stopper 41L, and the swing of the upper arm 31 is restricted. As described above, the wave receiving member 13 is configured to rock to the sea side by the force of avoiding waves when rocking beyond the first predetermined angle, as in the case of rocking to the breakwater side, and to restrict the operation of the upper arm 31 when rocking to the second predetermined angle, thereby exhibiting the same operational effects.

The

wave receiving mechanisms

10L and 10R configured as described above can allow the lower arm portion 32 to be bent with respect to the upper arm portion 31 by a simple operation of simply releasing the engagement between the hook 35 and the lower connecting body 34 b. This can suppress an increase in the number of components and manufacturing cost of the

wave receiving mechanisms

10L and 10R. When the upper arm portion 31 reaches the first predetermined angle only by swinging in a state where the release levers 39F and 39R are in contact with the locking pins 35a, the engagement between the hook 35 and the lower connecting body 34b is automatically released. Therefore, the release levers 39F and 39R and the ratchet 33 can be simply configured.

[ Flexible joints ]

In the wave power generation system 1 configured as described above, the support piles 3 may shake under the influence of waves because they are steel marine jacket structures. The support piles 3 rock with different behaviors, and as a result, the entire structure of the wave power generation system 1 is distorted. Due to this distortion, for example, the pair of support stands 11, 11 may be displaced forward or backward, and the rudder shaft 12 supported by them may be bent forward or backward. The steering shaft 12 used in the wave power generation system 1 has a length of about several to ten meters, and a displacement of only several to several tens of millimeters from one support 11 to the other support 11 generates an excessive load that acts on a connection portion connecting the steering shaft 12 and the pump shaft 21. Therefore, if the steering shaft 12 and the pump shaft 21 are fixedly connected, the connection portion may be damaged by the load.

In the wave power generation system 1, the input waves and the reflected waves do not necessarily contact the wave receiving plates 15 of the two

wave receiving mechanisms

10L and 10R perpendicularly, and may enter the wave receiving plates 15 at an angle, that is, obliquely. When the light enters obliquely in this way, a phase difference occurs between the rotations of the two steering shafts 12, and the pump shaft 21 connected to both ends thereof is twisted. Such a problem does not occur when the wave is small, but since the torsional force applied to the pump shaft 21 increases as the wave increases, the pump shaft 21 may be damaged when a large wave is generated as in the case of the typhoon described above.

Therefore, in the wave power generation system 1, in order to avoid the above-described situation, the steering shaft 12 and the pump shaft 21 are coupled by the flexible joint 16 as shown in fig. 1. The flexible joint 16, as described above, transmits the rotational force of the rudder shaft 12 to the pump shaft 21 while allowing the deflection and torsion of the rudder shaft 12 with respect to the pump shaft 21. The structure of the flexible joint 16 having such a function will be described in detail below.

In each of the

wave receiving mechanisms

10L and 10R, the other end of the steering shaft 12 and the two end of the pump shaft 21 face each other, and

flanges

12a and 21a are formed at these ends to form the flexible joint 16. That is, as shown in fig. 12, a substantially annular rudder side flange 12a is formed on the other end portion of the rudder shaft 12, and the rudder side flange 12a is formed so as to project radially outward around the entire circumference in the circumferential direction. As shown in fig. 13, the rudder side flange 12a has a plurality of pin holes 12b (eight pin holes 12b in the present embodiment) formed therein at equal intervals in the circumferential direction. The plurality of pin holes 12b penetrate the rudder side flange 12a so as to be parallel to the axis of the rudder shaft 12, and a torque pin 43 is fitted into each of the plurality of pin holes 12b to connect the two

flanges

12a and 21a to each other. The pump side flange 21a located on the pump shaft 21 is formed as follows so as to be able to be connected to the rudder side flange 12 a.

That is, the pump-side flanges 21a are formed on both ends of the pump shaft 21 so as to abut against the rudder-side flanges 12a, respectively, as described above. The pump-side flange 21a is formed by projecting both ends of the pump shaft 21 radially outward around the entire circumference thereof. The pump-side flange 21a thus formed is formed in a substantially annular shape in the same manner as the rudder-side flange 12a, and the outer diameter thereof is also the same as the outer shape of the rudder-side flange 12 a. The pump-side flange 21a having such a shape abuts against the rudder-side flange 12a so as to overlap each other when viewed from the axial direction.

The pump-side flange 21a has a plurality of bushing holes 21b (eight bushing holes 21b in the present embodiment) formed at equal intervals in the circumferential direction. More specifically, the plurality of bushing holes 21b are formed to correspond to the plurality of pin holes 12b of the rudder-side flange 12a, and the corresponding holes 12b and 21b communicate with each other in a state where the two

flanges

12a and 21a are butted against each other. The bushing hole 21b formed in this manner is formed to have a larger diameter than the pin hole 12b, and the damper bushing 44 is fitted into each of the bushing holes 21 b.

The damper bushing 44 is formed in a substantially cylindrical shape, and is configured to be able to insert the torque pin 43 therein. The damper bushing 44 is configured, for example, as follows. That is, the damper bushing 44 has an inner cylinder and an outer cylinder of metals having different outer diameters, and is configured by inserting the inner cylinder into the outer cylinder and vulcanizing and bonding them with synthetic rubber. The outer cylinder and the inner cylinder are disposed apart from each other so that the synthetic rubber interposed therebetween has a predetermined thickness. That is, the damper bushing 44 allows the inner tube to be relatively displaced with respect to the outer tube in the direction orthogonal to the axis thereof by elastic deformation of the synthetic rubber. The damper bushes 44 thus configured are inserted into the eight bush holes 21b, respectively, as described above. The damper bushing 44 has an inner diameter (i.e., an inner diameter of the inner cylinder) substantially equal to an outer diameter of the torque pin 43, and the torque pin 43 can be inserted therein.

In the flexible joint 16 thus configured, the two

flanges

12a, 21a abut against each other, and the two corresponding holes 12b, 21b also abut against each other. A torque pin 43 is inserted into each pin hole 12b, and a head portion of the torque pin 43 formed at a base end portion thereof is fastened and fixed to the rudder-side flange 21a by a bolt or the like, not shown. The torque pin 43 thus fixed is formed longer than the pin hole 12b in size, and its tip end side portion protrudes from the pin hole 12 b. The tip end portion extends to the damper bushing 44, and is embedded in the damper bushing 44. In this way, the torque pins 43 are inserted into the holes 12b and 21b and arranged at equal intervals in the circumferential direction on the two

flanges

12a and 21 a. Accordingly, the two

flanges

12a and 21a cannot be coupled to each other (that is, the two

shafts

12 and 21 cannot be coupled to each other), and the torque of the steering shaft 12 is reliably transmitted to the pump shaft 21.

The two

shafts

12 and 21 are coupled by the eight torque pins 43 arranged at equal intervals in the circumferential direction as described above, and each of the eight torque pins 43 is fitted to the pump-side flange 21a via the damper bushing 44. Thus, all the torque pins 43 can be relatively displaced with respect to the pump-side flange 21a in any direction orthogonal to the axis of the pump shaft 21, and can be absorbed by the damper bushes 44. Therefore, although the rudder shaft 12 has a deflection as described above, in doing so, the deflection of the rudder shaft 12 can be absorbed by the damper bushing 44. That is, the deflection load due to deflection can be suppressed from being transmitted to the pump shaft 21, and the pump device 20 can be suppressed from being damaged by such a deflection load.

In this case, the torque pin 43 is displaced in the circumferential direction in accordance with the twist of the rudder shaft 12 and is absorbed by the damper bushing 44. Therefore, even if the steering shaft 12 is twisted, the twisting torque is suppressed from being transmitted to the pump shaft 21, and the pump shaft 21 is twisted to suppress damage to the pump device 20.

In the wave power generation system 1, by interposing the flexible joint 16 between the two

shafts

12 and 21, even when the rudder shaft 12 is bent or twisted, the flexible joint 16 can absorb the deflection and the torsion. This can suppress damage to the steering shaft 12 and the pump shaft 21 even when the steering shaft 12 is bent or twisted.

< other embodiment >

In the wave power generation system 1 according to the present embodiment, the pair of

cylinder mechanisms

22U and 22D are arranged with a vertical interval therebetween, but this is not always necessary, and may be arranged with a horizontal interval therebetween. The pump device 20 does not necessarily need to include the two

cylinder mechanisms

22U and 22D, and may be one.

In the wave power generation system 1, the

wave receiving mechanisms

10R and 10L are disposed on both the left and right sides of the pump device 20, but need not necessarily be disposed on both the left and right sides, and may be disposed only on either the left or right side. The pump device 20 may be disposed between the pair of

arms

14 and 14. The pump device 20 is not necessarily limited to the plunger cylinder type, and may be configured to be capable of discharging the working fluid by swinging the wave receiving member 13.

In the wave power generation system 1, the control shaft 12 and the pump shaft 21 are formed of separate shafts, but may be formed of one shaft. The wave receiving member 13 is attached to the steering shaft 12 in a suspended manner, but may be configured as follows. That is, the control shaft 12 may be erected on the seabed so as not to be relatively provided to the control shaft 12 so as to extend in a direction (i.e., radial direction) orthogonal to the control shaft 12. The wave receiving member 13 includes a pair of

arms

14 and 14 for mounting the wave receiving plate 15, but one arm 14 may be provided.

The

wave receiving mechanisms

10L and 10R are configured such that the wave receiving member 13 is bent at the middle portion thereof by the ratchet 33, but the bent structure is not limited to the ratchet 33. The structure for releasing the engagement of the ratchet 33 is not necessarily limited to the release levers 39F and 39R, and may be a structure in which disengagement is performed based on a release command using an electric actuator or the like. In the

wave receiving mechanisms

10L and 10R, the swing of the wave receiving member 13 is limited by the stopper member, but the limitation is not necessarily required.

In the

wave receiving mechanisms

10L, 10R, the roller 38 is provided at the tip end side portions of the pair of hooks 35, but is not necessarily provided. For example, the engaging portions 34e of the lower connecting body 34b may be provided. In this case, the same operational effect as in the case where the roller 38 is provided at the tip end side portions of the pair of

hooks

35, 35 is exhibited. The

wave receiving mechanisms

10L and 10R do not necessarily need to be provided with the roller 38. For example, a coating may be applied to facilitate sliding at the engaged portion 34e, and the engagement and the disengagement may be facilitated as a sliding surface.

In the wave power generation system 1, the control shaft 12 and the pump shaft 21 are connected by the flexible joint 16, but the flexible joint 16 is not limited to the above-described configuration, and may be a joint that can absorb at least one of deflection and torsion, such as a universal joint or a fluid coupling.

Description of the symbols:

1, a wave power generation system;

10L and 10R wave receiving mechanisms;

12 rudder shaft (rudder craft);

13 a wave receiving member;

14 arms;

15 wave receiving plate;

16 flexible joints (flexible joints);

20 pump devices (hydraulic pumps);

21a pump shaft;

25 rods;

31 an upper arm portion (first arm portion);

32 lower arm portions (second arm portions);

33 ratchet (foldable part);

34e is engaged with the engaging portion;

35, a hook;

35a locking pin;

38 rollers (active side);

39F front release lever;

39R rear release lever;

41F front side stop;

41R rear side stopper.

Claims

1. A wave receiving mechanism is characterized in that,

the disclosed device is provided with: a shaft which is rotatably supported while being connected to a hydraulic pump and which drives the hydraulic pump by rotating in one circumferential direction and in the other circumferential direction; and

a wave receiving member that includes an arm that is attached to the shaft so as to be relatively non-rotatable, and a wave receiving plate that is provided on the arm so as to receive a force of a wave, and that receives the force of the wave to rock the shaft about the shaft and swing the shaft by rocking;

the arm has a first arm portion attached to the shaft so as not to be relatively rotatable, a second arm portion provided with the wave receiving plate, and a foldable portion connecting the first arm portion and the second arm portion;

the foldable portion is configured to rock the first arm integrally with the second arm when the swing angle of the first arm is smaller than a first predetermined angle, and to allow the second arm to be folded with respect to the first arm when the swing angle of the first arm is the predetermined angle.

2. A wave-receiving mechanism according to claim 1,

the foldable portion includes an engaging portion provided on one of the first arm and the second arm and an engaged portion provided on the other of the first arm and the second arm and engaged with the engaging portion, and the first arm and the second arm are integrally swung by engaging the engaging portion and the engaged portion, and the second arm is allowed to be folded with respect to the first arm by releasing the engagement of the engaging portion and the engaged portion.

3. A wave-receiving mechanism according to claim 2,

the wave receiving member includes a first arm portion that is pivotally connected to the housing, and a second arm portion that is pivotally connected to the first arm portion and that is pivotally connected to the housing.

4. A wave-receiving mechanism according to claim 3,

one of the engaging portion and the engaged portion has a roller rotatably supported by a portion with which the other member is engaged;

the roller rolls on the other member when the engagement between the engaging portion and the engaged portion is released.

5. A wave-receiving mechanism according to any one of claims 1 to 4,

the swing control device further includes a stopper member that is brought into contact with the first arm when the first arm is swung to a second predetermined angle equal to or greater than the first predetermined angle, and that limits the swing of the first arm.

6. A wave-receiving mechanism according to any one of claims 1 to 5,

a flexible joint connecting a wave receiving shaft as the shaft and a pump shaft of the hydraulic pump in a manner that their axes are parallel to each other;

the flexible joint allows relative displacement of the wave receiving axis with respect to the pump shaft in a direction orthogonal to the axis.